ON UPDATE CURRENT_TIMESTAMP is invalid

MYSQL updatetime The field is set to ON UPDATE CURRENT_TIMESTAMP

But after performing the UPDATE operation, the time in the database is still the time when it was added. What may be the cause?

public function updateInfo($cid,$data){
        $this->db->set($data);
        $this->db->where('cid',$cid);
        if($this->db->update('report')){
            return TRUE;
        } else {
            return FALSE;
        }
    }

Reply content:

MYSQL updatetime The field is set to ON UPDATE CURRENT_TIMESTAMP

But after performing the UPDATE operation, the time in the database is still the time when it was added. What may be the cause?

public function updateInfo($cid,$data){
        $this->db->set($data);
        $this->db->where('cid',$cid);
        if($this->db->update('report')){
            return TRUE;
        } else {
            return FALSE;
        }
    }

It may be that the data in your update this time is completely consistent with the database table data, and the affected rows may be 0.